Exception handling for autonomous vehicles

Abstract

Aspects of the technology relate to exception handling for a vehicle. For instance, a current trajectory for the vehicle and sensor data corresponding to one or more objects may be received. Based on the received sensor data, projected trajectories of the one or more objects may be determined. Potential collisions with the one or more objects may be determined based on the projected trajectories and the current trajectory. One of the potential collisions that is earliest in time may be identified. Based on the one of the potential collisions, a safety-time-horizon (STH) may be identified. When a runtime exception occurs, before performing a precautionary maneuver to avoid a collision, waiting no longer than the STH for the runtime exception to resolve.

The invention claimed is: 
     
       1. A method of exception handling for a vehicle, the method comprising:
 recieving, by the one or more processors, sensor data generated by a perception system of the vehicle having a sensor, wherein the sensor data corresponds to an object in an area surrouding a vehicle; 
 estimating, by the one or more processors, a protential collision with the object based on a current trajectory being followed by the vehicle; 
 determining, by the one or more processors, based on the potential collision, a safety-time-horizon (STH); 
 when a runtime exception occurs, continuing, by the one or more processors, to follow the current trajectory until the STH is reached; and 
 when the STH is reached and the runtime exception has not resolved, performing, by the one or more processors, a precautionary maneuver to avoid a collision with the object. 
 
     
     
       2. The method of  claim 1 , wherein determining the STH enables the vehicle to perform the precautionary maneuver before an expected time of the potential collision. 
     
     
       3. The method of  claim 1 , wherein determining the STH is based on an exception handling speed profile. 
     
     
       4. The method of  claim 3 , wherein the exception handling speed profile is a constant amount of deceleration for the vehicle. 
     
     
       5. The method of  claim 3 , wherein the exception handling speed profile corresponds to one or more changes to an amount of deceleration for the vehicle. 
     
     
       6. The method of  claim 1 , further comprising, periodically redetermining the STH prior to performing the precautionary maneuver as new sensor data is received. 
     
     
       7. The method of  claim 1 , wherein the runtime exception corresponds to a communication delay from the sensor. 
     
     
       8. The method of  claim 1 , wherein the runtime exception corresponds to lack of communication from the sensor of the perception system for a predetermined period of time. 
     
     
       9. The method of  claim 1 , wherein the precautionary maneuver includes one of pulling over or stopping the vehicle. 
     
     
       10. A system for exception handling for a vehicle, the system comprising one or more processors configured to:
 receive sensor data generated by a perception system of the vehicle having a sensor, wherein the sensor data corresponds to an object in an area surrounding a vehicle; 
 
       estimate a potential collision with the object based on a current trajectory being followed by the vehicle;
 determine based on the potential collision, a safety-time-horizon (STH); 
 when a runtime exception occurs, continue to follow the current trajectory until the STH is reached; and 
 when the STH is reached and the runtime exception has not resolved, perform a precautionary maneuver to avoid a collision with the object. 
 
     
     
       11. The system of  claim 10 , wherein the one or more processors are further configured to determine the STH in order to enable the vehicle to perform the precautionary maneuver before an expected time of the potential collision. 
     
     
       12. The system of  claim 10 , wherein the one or more processors are further configured to determine STH based on an exception handling speed profile. 
     
     
       13. The system of  claim 12 , wherein the exception handling speed profile is a constant amount of deceleration for the vehicle. 
     
     
       14. The system of  claim 12 , wherein the exception handling speed profile corresponds to one or more changes to an amount of deceleration for the vehicle. 
     
     
       15. The system of  claim 10 , wherein the one or more processors are further configured to periodically determine the STH prior to performing the precautionary maneuver as new sensor data is received. 
     
     
       16. The system of  claim 10 , wherein the runtime exception corresponds to a communication delay from the sensor. 
     
     
       17. The system of  claim 10 , wherein the runtime exception corresponds to lack of communication from the sensor of the perception system for a predetermined period of time. 
     
     
       18. The system of  claim 10 , wherein the precautionary maneuver includes one of pulling over or stopping the vehicle. 
     
     
       19. The system of  claim 10 , further comprising the vehicle.